gamemap.java

J2ME 上的坦克大战的demo,欢迎大家用来学习使用

/*
 * Created on 2004-10-24
 * Author: Xuefeng, Copyright (C) 2004, Xuefeng.
 */
package com.javaeedev.j2megame.tank;

import javax.microedition.lcdui.*;
import javax.microedition.lcdui.game.*;

/**
 * Hold a map.
 * 
 * @author Xuefeng
 */
public class GameMap extends TiledLayer {

    public static final int TILE_WIDTH = 8;
    public static final int MAP_WIDTH = 22;
    public static final int MAP_HEIGHT = 22;

    // a tile take 1 and a tank will take 4:
    public static final int TILE_TANK  = 6;

    public static final int TILE_EMPTY = 0;
    public static final int TILE_TREE  = 1;
    public static final int TILE_ICE   = 2;
    public static final int TILE_BRICK = 3;
    public static final int TILE_ROCK  = 4;
    public static final int TILE_RIVER = 5;

    // map data:
    private int[][] map;

    /**
     * Load the map resource. <code>col</code> and <code>row</code> specify the visible region's tiles.
     * 
     * @param map The int[][] array.
     */
    public GameMap(int[][] map, Image image) {
        super(MAP_WIDTH, MAP_HEIGHT, image, TILE_WIDTH, TILE_WIDTH);
        this.map = map;
        System.out.println("Map info: width = " + map[0].length + ", height = " + map.length);
        for(int x=0; x<MAP_WIDTH; x++) {
            for(int y=0; y<MAP_HEIGHT; y++) {
                setCell(x, y, map[y][x]);
            }
        }
    }

    private void setEmpty(int x, int y) {
        map[y][x] = TILE_EMPTY;
        setCell(x, y, TILE_EMPTY);
    }

    public int getTile(int x, int y) {
        return map[x][y];
    }

    public boolean canMoveLeft(int curr_x, int curr_y, int obj_width, int obj_height) {
        if(curr_x>0)
            return canSet(curr_x-1, curr_y, obj_width, obj_height);
        return false;
    }

    public boolean canMoveRight(int curr_x, int curr_y, int obj_width, int obj_height) {
        if(curr_x<MAP_WIDTH-obj_width) {
            return canSet(curr_x+1, curr_y, obj_width, obj_height);
        }
        return false;
    }

    public boolean canMoveUp(int curr_x, int curr_y, int obj_width, int obj_height) {
        if(curr_y>0) {
            return canSet(curr_x, curr_y-1, obj_width, obj_height);
        }
        return false;
    }

    public boolean canMoveDown(int curr_x, int curr_y, int obj_width, int obj_height) {
        if(curr_y<MAP_HEIGHT-obj_height) {
            return canSet(curr_x, curr_y+1, obj_width, obj_height);
        }
        return false;
    }

    /**
     * If a object is set to (x, y), with its size (obj_width, obj_height), 
     * can it be set to map?
     * 
     * @param x
     * @param y
     * @param obj_width
     * @param obj_height
     * @return
     */
    private boolean canSet(int x, int y, int obj_width, int obj_height) {
        for(int i=0; i<obj_width; i++) {
            for(int j=0; j<obj_height; j++) {
                if( map[y+j][x+i]>TILE_ICE )
                    return false;
            }
        }
        return true;
    }

    /**
     * Move object to the map(x, y).
     * 
     * @param layer Layer object.
     * @param x Position x in map.
     * @param y Position y in map.
     */
    public void setPosition(Layer layer, int x, int y) {
        layer.setPosition(x*TILE_WIDTH, y*TILE_WIDTH);
    }

    /**
     * Check if a bullet can pass:
     * @param x
     * @param y
     * @return
     */
    public boolean canPass(int direction, int x, int y) {
        int nx = x / TILE_WIDTH;
        int ny = y / TILE_WIDTH;
        System.out.println("canPass? x=" + x + ", y=" + y);
        boolean hit = false;
        switch(direction) {
        case Canvas.UP:
        case Canvas.DOWN:
            if(map[ny][nx]==TILE_EMPTY && map[ny][nx-1]==TILE_EMPTY)
                return true;
            if(map[ny][nx]==TILE_BRICK) {
                setEmpty(nx, ny);
                hit = true;
            }
            if(map[ny][nx-1]==TILE_BRICK) {
                setEmpty(nx-1, ny);
                hit = true;
            }
            if(hit)
                return false;
            break;
        case Canvas.LEFT:
        case Canvas.RIGHT:
            if(map[ny][nx]==TILE_EMPTY && map[ny-1][nx]==TILE_EMPTY)
                return true;
            if(map[ny][nx]==TILE_BRICK) {
                setEmpty(nx, ny);
                hit = true;
            }
            if(map[ny-1][nx]==TILE_BRICK) {
                setEmpty(nx, ny-1);
                hit = true;
            }
            if(hit)
                return false;
            break;
        }
        return false;
    }
}